ObjectiveThis study leverages structural data from antigen-antibody complexes of the influenza A virus neuraminidase (NA) protein to investigate the spatial recognition relationship between the antigenic epitopes and antibody paratopes. MethodsStructural data on NA protein antigen-antibody complexes were comprehensively collected from the SAbDab database, and processed to obtain the amino acid sequences and spatial distribution information on antigenic epitopes and corresponding antibody paratopes. Statistical analysis was conducted on the antibody sequences, frequency of use of genes, amino acid preferences, and the lengths of complementarity determining regions (CDR). Epitope hotspots for antibody binding were analyzed, and the spatial structural similarity of antibody paratopes was calculated and subjected to clustering, which allowed for a comprehensively exploration of the spatial recognition relationship between antigenic epitopes and antibodies. The specificity of antibodies targeting different antigenic epitope clusters was further validated through bio-layer interferometry (BLI) experiments. ResultsThe collected data revealed that the antigen-antibody complex structure data of influenza A virus NA protein in SAbDab database were mainly from H3N2, H7N9 and H1N1 subtypes. The hotspot regions of antigen epitopes were primarily located around the catalytic active site. The antibodies used for structural analysis were primarily derived from human and murine sources. Among murine antibodies, the most frequently used V-J gene combination was IGHV1-12*01/IGHJ2*01, while for human antibodies, the most common combination was IGHV1-69*01/IGHJ6*01. There were significant differences in the lengths and usage preferences of heavy chain CDR amino acids between antibodies that bind within the catalytic active site and those that bind to regions outside the catalytic active site. The results revealed that structurally similar antibodies could recognize the same epitopes, indicating a specific spatial recognition between antibody and antigen epitopes. Structural overlap in the binding regions was observed for antibodies with similar paratope structures, and the competitive binding of these antibodies to the epitope was confirmed through BLI experiments. ConclusionThe antigen epitopes of NA protein mainly ditributed around the catalytic active site and its surrounding loops. Spatial complementarity and electrostatic interactions play crucial roles in the recognition and binding of antibodies to antigenic epitopes in the catalytic region. There existed a spatial recognition relationship between antigens and antibodies that was independent of the uniqueness of antibody sequences, which means that antibodies with different sequences could potentially form similar local spatial structures and recognize the same epitopes.

Objective: To analyze the distribution and related factors of spherical equivalent(SE) anisometropia in school aged children in ethnic minority areas of Yunnan Province, so as to provide a scientific basis for the intervention and control of SE anisometropia. Methods: In October 2021,a total of 1 852 school aged children in three counties/cities(Lijiang City,Dali City,Xishuangbanna) in Yunnan Province were examined by multi stage cluster random sampling method for computer optometry visual acuity examination for non ciliary paralysis and questionnaire survey.Demographic characteristics, ocular biological parameters and SE data were obtained for SE anisometropia. Group comparisons were conducted using Mann-Whitney U test or Kruskal-Wallis H test, and Logistic regression was used to explore the related factors of anisometropia in SE. Results: The prevalence of SE anisometropia among school age children was 23.0%, and the prevalence was higher in girls (24.2%) than that in boys (21.6%). Compared with non anisometropic children, school aged children with SE anisometropia had longer axial length (AL) [24.03 (23.41, 24.76), 23.93 (23.26, 24.61) mm] and corneal curvature radius (CR) [43.42 (42.43, 44.42), 43.14 (42.23, 44.04)mm], SE[-1.75(-2.75,-1.00),-0.94(-2.63,-0.25)D], smaller spherical scope [-1.38(-2.38,-0.75),-0.75(-2.38,0)D], deeper anterior chamber depth(ACD)[3.77(3.62, 3.93), 3.72(3.55, 3.89)mm], and grater differences in AL[0.58(0.32,0.82), 0.13( 0.06 ,0.22)mm], ACD[0.05(0.02,0.08), 0.03(0.01,0.06)mm] and AL/CR[0.01(0.01,0.02), 0.01(0.00,0.01)]( Z =-22.47 to -2.41, all P <0.05). The results of Logistic regression showed that mild myopia( OR =2.74), moderate myopia( OR =3.52), and high myopia( OR =8.92) had a relatively high risk of anisometropia SE in school aged children(all P <0.05). Conclusion The prevalence of SE anisometropia in school aged children in ethnic minority areas of Yunnan Province is relatively high, and the prevalence and degree of anisometropia were closely related to myopia degree and related refractive parameters.

Background::Programmed death 1 (PD-1) blockade plus chemotherapy has become the new first-line standard of care for patients with advanced non-small-cell lung cancer (NSCLC). Yet not all NSCLC patients benefit from this regimen. This study aimed to investigate the predictors of PD-1 blockade plus chemotherapy in untreated advanced NSCLC.Methods::We integrated clinical, genomic, and survival data from 287 patients with untreated advanced NSCLC who were enrolled in one of five registered phase 3 trials and received PD-1 blockade plus chemotherapy or chemotherapy alone. We randomly assigned these patients into a discovery cohort ( n = 125), a validation cohort ( n = 82), and a control cohort ( n = 80). The candidate genes that could predict the response to PD-1 blockade plus chemotherapy were identified using data from the discovery cohort and their predictive values were then evaluated in the three cohorts. Immune deconvolution was conducted using transcriptome data of 1014 NSCLC patients from The Cancer Genome Atlas dataset. Results::A genomic variation signature, in which one or more of the 15 candidate genes were altered, was correlated with significantly inferior response rates and survival outcomes in patients treated with first-line PD-1 blockade plus chemotherapy in both discovery and validation cohorts. Its predictive value held in multivariate analyses when adjusted for baseline parameters, programmed cell death ligand 1 (PD-L1) expression level, and tumor mutation burden. Moreover, applying both the 15-gene panel and PD-L1 expression level produced better performance than either alone in predicting benefit from this treatment combination. Immune landscape analyses revealed that tumors with one or more variation in the 15-gene panel were associated with few immune infiltrates, indicating an immune-desert tumor microenvironment.Conclusion::These findings indicate that a 15-gene panel can serve as a negative prediction biomarker for first-line PD-1 blockade plus chemotherapy in patients with advanced NSCLC.

Aim To design and synthesize a series of phenylacetamide derivatives with different substituted phenylacetic acid as raw materials,and to investigate the protective effects of the compound on the damage of pancreatic β cells induced by palmitate acid(PA).Methods Min6 cells were cultured and divided into B blank control group,PA treatment group and PA+compounds group.The viability of Min6 cells was de-tected by CCK-8.The protein expressions of TXNIP and NLRP3 were observed by Western blot.MDA con-tent and SOD activity were detected by MDA and SOD kit.The insulin secretion of Min6 islet cells was meas-ured with insulin ELISA kit.Results A total of 10 phenylacetamide derivatives were designed and synthe-sized.Their structures were confirmed by 1H NMR and ESI-MS.Pharmacological activity study showed that most of the compounds had protective effects on islet βcells,among which LY-6 and LY-8 had stronger pro-tective effects than PA model group,with the cell via-bility of 61.4％,and LY-6 had the highest cell activi-ty,reaching to 104.9％.Compared with PA group,the protein expression of TXNIP and NLRP3 decreased in LY-6 and LY-8 groups,MDA content decreased and SOD activity increased,and insulin secretion of Min6 cell increased.Conclusions LY-6 and LY-8 inhibit TXNIP expression and decrease the activation of NL-RP3 inflammasome,and decrease the production of MDA and increase SOD activity,and thus reducing is-let β cells apoptosis and increasing insulin secretion.Therefore,the compound LY-6 could serve as a poten-tial anti-diabetic new chemical entity.

Aim To explore the protective effects of Xiyanping injection against lipopolysaccharide(LPS)-induced acute lung injury(ALI)in mice,and investi-gate the underlying mechanism.Methods In the LPS-induced ALI mouse model,the protective effect of Xiyanping injection against ALI was evaluated by ob-serving the pathological indicators of lung tissue.Net-work pharmacology and molecular docking were used to explore its mechanism.Western blot method was used to validate the predicted target proteins.Results Xiy-anping injection significantly improved the pathological injury and alleviated inflammatory reactions in lungs of ALI mice.Four active ingredients were identified in Xiyanping injection,namely,14-deoxy-11-oxo-an-drographolide,14-deoxyandrographolide,14-deoxy-12-methoxyandrographolide,and andrographolide-19-β-D-glucoside.A total of 288 corresponding drug targets and 4 960 ALI-related targets were obtained,with 192 genes overlapping.The ten core targets associated with Xiyanping injection were identified as STAT3,EGFR,PIK3R1,MAPK1,PIK3CA,NFKB1,ESR1,MAPK8,JAK2,and FYN.GO enrichment analysis re-vealed 310 biological processes(BP),65 cellular components(CC),and 80 molecular functions(MF)associated with the overlapping genes.KEGG pathway enrichment analysis identified 141 pathways related to ALI,with the top 20 pathways including MAPK,TNF-α,VEGF,cAMP,mTOR,AMPK,NOD,JAK-STAT,IL-17,and NF-κB.Molecular docking results demonstrated strong binding affinity between core tar-gets(MAPK1,MAPK8,NFKB1)and active ingredi-ents(14-deoxy-12-methoxyandrographolide and 14-de-oxyandrographolide).Western blotting showed that medium and high doses of Xiyanping injection signifi-cantly downregulated p38,JNK,ERKl/2,NF-κB p65 protein expression in lung tissue of ALI mice(P＜0.01).Conclusions Xiyanping injection has a cer-tain protective effect against ALI,and the mechanism is related to regulating MAPK and NF-κB signaling pathways.

OBJECTIVE To establish a mouse model of diabetes mellitus(DM)combined with severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)infection to investigate the important pathophysiological changes in the development of DM combined with SARS-CoV-2 infection.METHODS Wild-type(WT)mice and transgenic mice expressing the human angiotensin-converting enzyme 2 receptor driven by the cytokeratin-18 gene promoter(K18-hACE2)were randomly divided into the control group,DM group,SARS-CoV-2 spike protein(S)infection group and DM combined with S protein infection group,with 10 to 12 mice in each group.All the mice were induced by 10 weeks of high-fat diet combined with 40 mg·kg-1 streptozotocin(STZ)for 3 days by ip,except those in the control group or S protein infection group.The control group was given the same volume of 0.1 mol·L-1 sodium citrate buffer.Mice in the S protein infection group and DM+S protein infection group were additionally given 50 μL mixture of 15 μg SARS-CoV-2 spike protein and 1 g·L-1 polyinosinic-polycytidylic acid(poly[I:C])via intranasal drops,while the control group was given an equal volume of sterile water.The glucose tolerance level and pancreatic islet β cell function of mice were evaluated via oral glucose tolerance test at the 6th week of high-fat feeding and 1 week after the administration of STZ by ip.From the 6th week of high-fat feeding to 2 weeks after the administration of STZ,the random blood glucose and fasting blood glucose of mice were measured by a blood glucose meter.Blood samples were taken from subman-dibular veins of 3 mice in each group at 24,48 and 120 h after S protein infection,and lung tissues were taken after euthanization.The pathological changes of lungs of DM mice before and after S protein infection were observed by HE staining.Except for the DM group,blood samples were collected before S protein infection and at 6,24,48,72 and 120 h after infection.The levels of plasma interleukin 1β(IL-1β),IL-2,IL-6,IL-10,IL-17,interferon gamma-induced protein 10(IP-10),interferon γ(IFN-γ),tumor necrosis factor α(TNF-α),monocyte chemotactic protein-1(MCP-1)and granulocyte-colony stimulating factor(G-CSF)were detected by Luminex.The plasma levels of heparan sulfate(HS)were measured by enzyme-linked immunosorbent assay.The levels of cytokines and HS were correlated with the degree of pathological damage by Spearman correlation analysis.RESULTS STZ and high-fat diet could induce DM-like expression in mice,and the random blood glucose(P<0.01)and fasting blood glucose(P<0.05)after 1 week in the hACE2-DM group were significantly higher than in the WT-DM group,and the degree of islet function damage in hACE2-DM mice was significantly higher than that of WT-DM mice(P<0.05).Compared with the DM group,the DM+S group showed more severe pulmonary pathological changes after S protein infection,accompanied by a large number of inflammatory infiltrations and thickening of lung interstitial.Compared with the control group,the levels of pro-inflammatory cytokines G-CSF,IL-6 and IP-10 in the plasma of the WT-S group were significantly increased at 6 h after S pro-tein infection(P<0.01),and those of pro-inflammatory cytokine IL-17 and anti-inflammatory cytokine IL-10 were significantly increased at 24 h after S protein infection(P<0.05).Compared with the control group,the plasma levels of pro-inflammatory cytokines IL-1β,IL-6,TNF-α,MCP-1,G-CSF and IP-10 in the hACE2-S group were significantly increased at 6 h after S protein infection(P<0.05,P<0.01).IL-17 was significantly increased at 24 h and 6 h after S protein infection in the WT-DM+S group and hACE2-DM+S group,respectively(P<0.01,P<0.05).In the hACE2-DM+S group,IFN-γ and IL-1β were signifi-cantly increased in delay to 48 h(P<0.05,P<0.01),and MCP-1 was significantly increased in delay to 72h(P<0.05).Compared with the control group,the level of HS in the plasma of the WT-S group increased significantly(P<0.05,P<0.01)at 6 h and 24 h after S protein infection,but began to decrease at 48 h.At the same time,compared with the WT-S group,the HS level in the WT-DM+S group was slightly increased at 6 h after infection and decreased at 24 h.Compared with the control group,the HS level in the hACE2-S group was significantly increased at 24 h(P<0.01),as was the case with the WT-S group 24 h,48 h and 120 h after S protein infection.At 6 h,24 h and 48 h after S protein infection,the plasma HS level of the hACE2-DM+S group was significantly increased(P<0.01,P<0.05),and the duration of the increase was longer than in the hACE2-S group.Moreover,the levels of IL-1β,IL-10,MCP-1,IP-10,G-CSF and HS in plasma were positively correlated with the degree of lung dam-age in the DM+S group.CONCLUSION In this study,the mouse model of diabetes combined with SARS-CoV-2 spike protein infection has mimicked part of the pathophysiological features of clinical patients,mainly manifested as blunted immune response and elevated HS levels with longer duration to infection alone.IL-1β,IL-10,MCP-1,IP-10,G-CSF and HS may keep track of the course of disease in patients with diabetes combined with SARS-CoV-2 infection.

Objective To monitor the susceptibility of clinical isolates to antimicrobial agents in tertiary hospitals in major regions of China in 2022.Methods Clinical isolates from 58 hospitals in China were tested for antimicrobial susceptibility using a unified protocol based on disc diffusion method or automated testing systems.Results were interpreted using the 2022 Clinical &Laboratory Standards Institute(CLSI)breakpoints.Results A total of 318 013 clinical isolates were collected from January 1,2022 to December 31,2022,of which 29.5％were gram-positive and 70.5％were gram-negative.The prevalence of methicillin-resistant strains in Staphylococcus aureus,Staphylococcus epidermidis and other coagulase-negative Staphylococcus species(excluding Staphylococcus pseudintermedius and Staphylococcus schleiferi)was 28.3％,76.7％and 77.9％,respectively.Overall,94.0％of MRSA strains were susceptible to trimethoprim-sulfamethoxazole and 90.8％of MRSE strains were susceptible to rifampicin.No vancomycin-resistant strains were found.Enterococcus faecalis showed significantly lower resistance rates to most antimicrobial agents tested than Enterococcus faecium.A few vancomycin-resistant strains were identified in both E.faecalis and E.faecium.The prevalence of penicillin-susceptible Streptococcus pneumoniae was 94.2％in the isolates from children and 95.7％in the isolates from adults.The resistance rate to carbapenems was lower than 13.1％in most Enterobacterales species except for Klebsiella,21.7％-23.1％of which were resistant to carbapenems.Most Enterobacterales isolates were highly susceptible to tigecycline,colistin and polymyxin B,with resistance rates ranging from 0.1％to 13.3％.The prevalence of meropenem-resistant strains decreased from 23.5％in 2019 to 18.0％in 2022 in Pseudomonas aeruginosa,and decreased from 79.0％in 2019 to 72.5％in 2022 in Acinetobacter baumannii.Conclusions The resistance of clinical isolates to the commonly used antimicrobial agents is still increasing in tertiary hospitals.However,the prevalence of important carbapenem-resistant organisms such as carbapenem-resistant K.pneumoniae,P.aeruginosa,and A.baumannii showed a downward trend in recent years.This finding suggests that the strategy of combining antimicrobial resistance surveillance with multidisciplinary concerted action works well in curbing the spread of resistant bacteria.

Objective To investigate the distribution and antimicrobial resistance profiles of the common pathogens isolated from urine from 2015 to 2021 in the CHINET Antimicrobial Resistance Surveillance Program.Methods The bacterial strains were isolated from urine and identified routinely in 51 hospitals across China in the CHINET Antimicrobial Resistance Surveillance Program from 2015 to 2021.Antimicrobial susceptibility was determined by Kirby-Bauer method,automatic microbiological analysis system and E-test according to the unified protocol.Results A total of 261 893 nonduplicate strains were isolated from urine specimen from 2015 to 2021,of which gram-positive bacteria accounted for 23.8％(62 219/261 893),and gram-negative bacteria 76.2％(199 674/261 893).The most common species were E.coli(46.7％),E.faecium(10.4％),K.pneumoniae(9.8％),E.faecalis(8.7％),P.mirabilis(3.5％),P.aeruginosa(3.4％),SS.agalactiae(2.6％),and E.cloacae(2.1％).The strains were more frequently isolated from inpatients versus outpatients and emergency patients,from females versus males,and from adults versus children.The prevalence of ESBLs-producing strains in E.coli,K.pneumoniae and P.mirabilis was 53.2％,52.8％and 37.0％,respectively.The prevalence of carbapenem-resistant strains in E.coli,K.pneumoniae,P.aeruginosa and A.baumannii was 1.7％,18.5％,16.4％,and 40.3％,respectively.Lower than 10％of the E.faecalis isolates were resistant to ampicillin,nitrofurantoin,linezolid,vancomycin,teicoplanin and fosfomycin.More than 90％of the E.faecium isolates were ressitant to ampicillin,levofloxacin and erythromycin.The percentage of strains resistant to vancomycin,linezolid or teicoplanin was＜2％.The E.coli,K.pneumoniae,P.aeruginosa and A.baumannii strains isolated from ICU inpatients showed significantly higher resistance rates than the corresponding strains isolated from outpatients and non-ICU inpatients.Conclusions E.coli,Enterococcus and K.pneumoniae are the most common pathogens in urinary tract infection.The bacterial species and antimicrobial resistance of urinary isolates vary with different populations.More attention should be paid to antimicrobial resistance surveillance and reduce the irrational use of antimicrobial agents.

Objective To understand the distribution and changing resistance profiles of clinical isolates of Enterococcus in hospitals across China from 2015 to 2021.Methods Antimicrobial susceptibility testing was conducted for the clinical isolates of Enterococcus according to the unified protocol of CHINET program by automated systems,Kirby-Bauer method,or E-test strip.The results were interpreted according to the Clinical & Laboratory Standards Institute(CLSI)breakpoints in 2021.WHONET 5.6 software was used for statistical analysis.Results A total of 124 565 strains of Enterococcus were isolated during the 7-year period,mainly including Enterococcus faecalis(50.7％)and Enterococcus faecalis(41.5％).The strains were mainly isolated from urinary tract specimens(46.9％±2.6％),and primarily from the patients in the department of internal medicine,surgery and ICU.E.faecium and E.faecalis strains showed low level resistance rate to vancomycin,teicoplanin and linezolid(≤3.6％).The prevalence of vancomycin-resistant E.faecalis and E.faecium was 0.1％and 1.3％,respectively.The prevalence of linezolid-resistant E.faecalis increased from 0.7％in 2015 to 3.4％in 2021,while the prevalence of linezolid-resistant E.faecium was 0.3％.Conclusions The clinical isolates of Enterococcus were still highly susceptible to vancomycin,teicoplanin,and linezolid,evidenced by a low resistance rate.However,the prevalence of linezolid-resistant E.faecalis was increasing during the 7-year period.It is necessary to strengthen antimicrobial resistance surveillance to effectively identify the emergence of antibiotic-resistant bacteria and curb the spread of resistant pathogens.

Objective To examine the changing antimicrobial resistance profile of Enterobacter spp.isolates in 53 hospitals across China from 2015 t0 2021.Methods The clinical isolates of Enterobacter spp.were collected from 53 hospitals across China during 2015-2021 and tested for antimicrobial susceptibility using Kirby-Bauer method or automated testing systems according to the CHINET unified protocol.The results were interpreted according to the breakpoints issued by the Clinical & Laboratory Standards Institute(CLSI)in 2021(M100 31st edition)and analyzed with WHONET 5.6 software.Results A total of 37 966 Enterobacter strains were isolated from 2015 to 2021.The proportion of Enterobacter isolates among all clinical isolates showed a fluctuating trend over the 7-year period,overall 2.5％in all clinical isolates amd 5.7％in Enterobacterale strains.The most frequently isolated Enterobacter species was Enterobacter cloacae,accounting for 93.7％(35 571/37 966).The strains were mainly isolated from respiratory specimens(44.4±4.6)％,followed by secretions/pus(16.4±2.3)％and urine(16.0±0.9)％.The strains from respiratory samples decreased slightly,while those from sterile body fluids increased over the 7-year period.The Enterobacter strains were mainly isolated from inpatients(92.9％),and only(7.1±0.8)％of the strains were isolated from outpatients and emergency patients.The patients in surgical wards contributed the highest number of isolates(24.4±2.9)％compared to the inpatients in any other departement.Overall,≤ 7.9％of the E.cloacae strains were resistant to amikacin,tigecycline,polymyxin B,imipenem or meropenem,while ≤5.6％of the Enterobacter asburiae strains were resistant to these antimicrobial agents.E.asburiae showed higher resistance rate to polymyxin B than E.cloacae(19.7％vs 3.9％).Overall,≤8.1％of the Enterobacter gergoviae strains were resistant to tigecycline,amikacin,meropenem,or imipenem,while 10.5％of these strains were resistant to polycolistin B.The overall prevalence of carbapenem-resistant Enterobacter was 10.0％over the 7-year period,but showing an upward trend.The resistance profiles of Enterobacter isolates varied with the department from which they were isolated and whether the patient is an adult or a child.The prevalence of carbapenem-resistant E.cloacae was the highest in the E.cloacae isolates from ICU patients.Conclusions The results of the CHINET Antimicrobial Resistance Surveillance Program indicate that the proportion of Enterobacter strains in all clinical isolates fluctuates slightly over the 7-year period from 2015 to 2021.The Enterobacter strains showed increasing resistance to multiple antimicrobial drugs,especially carbapenems over the 7-year period.